Printing head



AO ct. 29, 1963 I G. H. GREEN l 3,108,673

INVENTOR Lw MQW i G. H. GREEN PRINTING HEAD Oct. 29, 1963 v 4Sheets-Sheet 2 Filed Feb. 8. 1961 INVENTOR Oct. l29, 1963 A G. H. GREEN3,108,673

PRINTING HEAD Filed Feb. a. 19614 4 sheets-sheet :5

4.a 4.9 E 8 EB INVENTOR Oct. 29, 1963 G. H. GREEN 3,108,673

PRINTING HEAD lFiled Feb. 8, 1961 4 sheets-sheet 4 INVENTOR UnitedStates Patent O 3,103,673 PRINTING HEAD Gourley H. Green, CanadianResearch 8: Development Foundation, 1434 Queen St. W., Scarborough,Gntario, Canada Filed Feb. 8, 1961, Ser. No. 87,953 2 Claims. (Cl.197-1) This invention relates to improvements in printing devices, andmore particularly, to improvements in printing heads adapted to impresscharacters or the like upon tape or paper upon being actuated by anelectrical control device.

It is conventional practice to utilize teletype machines in thetransmission of messages between distant points. These machines have thedisadvantages that they are very expensive, they are extremelycomplicated and, on being used in combination with a typewritermechanism, are limited in their speed of operation by the mechanicallimitations of the typewriting machinery. Yet another disadvantage ofthis conventional method lies in the fact that transmission of messagesmust be made by an operator skilled in the art and is therefore limitedin scope and mobility.

It is also conventional practice to utilize printing devices totranscribe information emanating from electronic calculating machinesand the like, the disadvantage here being in the fact that thecalculator supplies infomation many times faster than the printingdevice can transcribe it. Printing heads adapted to operate at muchgreater speeds than those in current use have developed, but they havethe disadvantage of being highly complicated and extremely expensive.

It is an object of this invention to provide a printing head that mayreceive and translate electrical signals, either by wire or radio, thetranslation being in the form of printed characters on a sheet of paperor the like or other printing media.

It is another object of this invention to provide a printing head thatwill be able to print at high speed by utilizing the minimum number ofmoving parts.

It is yet another object of this invention to provide a printing headthat will cause messages to be printed in ink upon a sheet of paper orthe like.

It is a further object of this invention to provide a printing head thatwill be substantially compact and easily portable.

It is yet another object of this invention to provide a printing head,the operation of which is controlled by varying the frequencies of aradio or electrical signal.

It is yet another object of this invention to provide a printing headthat may be actuated by signals emanating from a tape recording.

It is still another object of this invention to provide a printing headthat will record and store information supplied to it, thereby allowingfor slower transcription and also providing an extremely compact methodof information storage and retrieval.

It is a further object of this invention to provide a printing head thatmay be actuated by radio frequency signals emanating from space vehiclesor the like, thereby providing a visual translation of the signals whichmay be quickly and easily decoded.

It is yet another object of this invention to provide a printing headwhich is far simpler' in operation and far less expensive thanconventional printing devices.

These and other objects and features of this invention will becomeapparent when taken in conjunction with the accompanying drawings inwhich:

FIG. l is a sectional view of a printing head embodylCC ing thisinvention, only ve pens being illustrated for purposes of clarity.

FIG. 2 is a fractional, sectional, side elevation of the actuatingmechanism for a pen assembly as illustrated in FIG. l.

FIG. 3 is a fractional, side elevation of the upper end of the printinghead as illustrated in FIG. 1, showing particularly the method by whichthe pen assemblies are connected with an ink reservoir.

FIG. 4 is a fractional, sectional, side elevation of a pen assembly asillustrated in FIG. l, showing particularly the method by which the penis connected to the ink reservoir at the upper end, and to the stylus atthe lower end thereof.

FIG. 5 is an end view of the printing head as illustrated in FIG. 1having the supporting discs partly cut away, thereby illustrating therelative positions of a plurality of pen assemblies contained therein.

FIG.V 6 is a diagrammatic sketch and wiring diagram illustrating themethod by which a printing head as illustrated in FIG. l, is actuated bythe changes in frequency of an electrical current.

FIG. 7 is a sectional view of the multiple switch assembly, taken on theline 7-7 of FIG. 6.

FIG. 8 is a plan View of a printing head as illustrated in FIG. 1, uponthe letter A being transmitted through the switch assembly asillustrated in FIGS. 6 and 7 causing a plurality of pens to descend, thenon-actuated pens being shown in phantom.

FIG. 9 is a fractional, sectional, side elevation of the stylus portionof the pens as illustrated in FIG. 8, taken on the line 9-9 of FIG. 8.

FIG. l0 is a fractional, plan view of a piece of paper or the like uponwhich the pen assemblies as illustrated in FIG. 8 have descended to formthe letter A.

FIG. l1 is a plan View of an alternative method of construction of theguide means for the stylus portions of the pen assemblies as illustratedin FIG. 1.

FIG. 12 is a mid sectional view of the guide means as illustrated inFIG. 1l, taken on the line 12-12.

Referring to FIG. 1, a printing head, indicated generally by arrow 20,comprises a hollow, cylindrical housing 21 having its upper end closedby an end cap 22. and its lower end by a disc 23 integral with walls 24of housing 21.

A square aperture 25 is formed substantially centrally in end disc 23and is surrounded by a wall 26 depending therefrom.

A plurality of shoulders 27 are formed on the inner surface of wall 24by means of wall 24 being stepped downwardly and inwardly, the maximuminternal diameter of housing 21 being adjacent cap 22 and the minimumdiameter being adjacent end disc 23. Shoulders 2'7 are in parallel,spaced apart relationship with each other and with the upper and lowersurfaces of housing 21, each shoulder 27 being adapted to support arigid diaphragm 28, and each diaphragm 28 being retained thereon bymeans of a spring ring 29, removably located within a mating groove 39formed in the walls 24 adjacent to and above each shoulder 27.

A square guide plate 3l is groovedly retained within aperture 25 inparallel, spaced apart relationship with diaphrams 2S.

A plurality of suitably hushed holes 32 lare formed in .cap 22 similarbushed holes 33 being formed in diaphrams 3 thereof will be permitted toslide vertically through a bushed hole 4t) formed in plate 31.

It may be seen that, due to the rigidity of tubes 34 vertical movementthereof will automatically result in similar vertical movement of thecorresponding stylus 35.

Referring to FlGS. 1 and 2, it may be seen that each tube 34 also passesvertically through the centre of ya hollow core electromagnet 36. Eachelectromagnet 36 is permanently attached to the upper surface of adiaphram 23, a plurality of clectromagnets 36 being substantiallyequally disposed on varying levels of diaphragms 2S to permitoverlapping thereof and greater compact-ness of the printing head 20.

A steel disc 37 is threadably engaged on each tube 34 and is adapted toremain in parallel, spaced :apart relationship with the upper surface ofelectromagnet 36 upon clectromagnet 36 being at rest. A coil spring 3Sis located around tube 34 and interposed between the upper surface ofelectromagnet 36 and the lower surface of steel disc 37. A lock nut 39`is vadapted falso to threadably engage tube 34 and maintain disc 37 ata predetermined distance above electromagnet 36.

lt may be seen, therefore, that upon an electrom-agnet 36 becomingenergized, its adjacent steel washer 37 will be attracted to it,overcoming spring 38, Iand the whole of tube 34 :and stylus 35 caused tomove vertically downwardly.

It should be noted that cap 22 as illustrated in HG. 1 is detachablyattached to the upper edge of walls 24 by 'suitable means such as, forinstance, a slotted flange 41 extending downwardly from the outer edgeof cap 22 to eng-age over horizontal bolts 42 extending outwardly ofwalls 24, wing nuts 43 being adapted to threadably engage bolts 42, and,by exerting a pressure on the side of flange 41, restrain cap 22 fromvertical movement. Flange 4i, being a close fit on walls 24, serves tolocate cap 22 horizontally thereupon.

Referring to FIG. 3, viscous ink ds supplied to tubes 34 from apressurized container 44 through a plurality of iiexible tubes 45.

Referring to FiGS. 3 and 4, the upper land lower extremities of a tube34 are illustrated, in which a resilient sleeve 46 is utilized to join`the upper end of tube 34 and the lower end of flexible tube 45 influid-tight relationship. lt may also be seen that stylus 35 is tubular,hiaving an ink passage 47 formed axially therethrough, of a much lesserdiameter than the interior of tube 34, so that, upon tube 34 beingcharged with ink, passage 47 will also contain ink but stylus 35 willdischarge ink only upon its tip `43 Corning into contact with anlabsorbent surface such as for instance, paper 49 as illustrated.

Referring to FlGS. 1, 2, 3 and 4, therefore, it may be seen that uponelectromagnet 36 becoming actuated and attracting steel disc 37 tube 34is caused to move downwardly, this movement being translated to downwardmovement of stylus 35 which, in turn, causes tip 48 to contact paper 49and imprint a dot of ink thereon.

As an alternative configuration, the tip 48 of each stylus 35 may beprovided with a plurality of outlets for the ink supply from passage 47so that a similar plurality of fine dots of ink :are imprinted on paper49 instead of one large dot as previously descnibed. This methodprovides :for a more even ink distribution over paper 49 and thecharacters imprinted thereon, therefore, present Va more pleasing andlegible appearance.

Referring to FIG. 5, an arrangement is illustrated in `which tubes 34`are contained within housing 21, their Vstyli being larranged in `afive by ve square pattern so that, upon a number of tubes 34 beingactuated by their electromagnets 36 a number of styli 35 may protrudedownwardly, placing a series of ink dots simultaneously upon paper 49,and -thereby forming the outline of a letter, figure or other vsymbol ina predetermined pattern.

It .should be noted that the ntie square arrangement as illustrated inFiG. 5 has been adopted for purposes of clarity in illustration and thisis in no way intended to limit the scope of ythe invention, the numberand arrangement of tubes 34 md styli 35 being contingent upon thedensity of print required by the Operator.

Referring to FIG. 6, the 25 electromagnets 36 required to operate :thetubes 34 as illustrated in FIG. S are shown in diagrammatic form, andthe method by which a plurality of electromagnets 36 are activated tocause a predetermined character to become printed is also shown indiagrammatic form.

A tape recorder 51 is adapted to receive and record signals from -atransmitting source, the signals being in the form of changingfrequencies, each character having its own individual frequency, acoaxial cable or the like being utilized to supply a varying frequencyelectrical current to :tape recorder 51, or tape recorder 51 may beadapted Ito receive land record varying nadio frequencies received froma conventional transmitter.

The tape upon which the frequency changes are recorded may then beplayed back through a transducer 52.

Transducer 52 is adapted to utilize a particular frequency to actuateone particular solenoid switch 53 contained within a multiple switchassembly 54. A plurality of switches 53 are contained within switchassembly 54, there being one switch 53 for each character which may bcdesired to be imprinted by ,printing head 20. As previously stated, eachswitch 53 is actuated by its own frequency as selected by transducer 52.

One terminal of each electromagnet 36 is connected to a source ofelcctnical energy such as, for instance, -a battery 55. The oppositeterminals are extended and each connected to a wire 56 so that, in thisinstance, 25 wires 56 Aare located in substantially coplanar, parallel,spaced apart relationship within the base of switch assembly 54.

Referring to FIGS. 6 and 7, wires 56 are illustrated as being retainedwithin the insulated base 57 of switch assembly 54 and the constructionand operation of one solenoid switch 53 is illustrated. As previouslystated, each switch 53 is adapted to selecta predetermined number ofstyli 35 to contact paper 49 and imprint thereon a predeterminedcharacter. Thus, :the corresponding electromagnets 36 must be actuatedand, therefore, the wires 56 connecting these specific electromagnets 36must be permitted to close the electric circuit from battery 55.

Switch 53 comprises a conventional solenoid 5S having a square sectioncore 59 activated by an actuator Gti contained within transducer 52. Anarrow, flat bar 61 of rigid insulating material having a strip 62'. ofelectrical conducting material permanently attached to the undersurfacethereof is attached to the upper end of core 59 of solenoid 53. Thesquare section of core 59 ensures that bar 61 and its attendant strip 62remain in the same vertical plane at all times and prevents rotationthereof in the horizontal plane. A light spring 63 surrounds core 59 andis placed between the upper surface of base 57 and the lower surface ofstrip 62 causing strip 62 and base 57 Ito remain in parallel, spacedapart relationship until the pressure of spring 63 is overcome byactuation of solenoid 58. A plurality of electrically conductive studs64, in transverse alignment, extend upwardly from selected wires 56 toterminate above the upper surface of base 57. A further connector studis also adapted to stand proud of the upper surface of base 57, itsopposite end being connected to battery 55. Studs 64 and 65 are allsubstantially the same height above the upper surface of base 57.

Upon actuators 60 within transducer 52 selecting a particular character,its solenoid 58 becomes activated causing core 59 to move inwardlythereof, overcoming spring 63 and bringing conductor strip 62 intocontact with the tops of studs 64 and interconnecting them with the topof connector stud 65. Thus, a plurality of parallel, electrical circuitswill be completed through switch 53 causing a corresponding plurality ofelectromagnets 36 to be activated within printing head 2G, therebycausing the related tubes 34 lto move downwardly and their attachedstyli 4S to imprint the required character upon paper 49.

It should be noted that one solenoid switch 53 is utilized for eachcharacter which may require to be printed.

With reference to FIGS. 8, 9 and 10, the operation by which the letter Ais printed is illustrated. The required styli 35, as shown in FIGS. 8and 9, have been caused to move through guide plate 31 and extend beyondthe non-activated styli 35, the tips 48 of the activated styli 35 cominginto contact with the upper surface of sheet of paper 49. FIG. 10illustrates the impression made on paper 49 and it may be seen that aplurality of dots outline the required letter A.

Referring to FIGS. 11 and 12, an alternative means of supporting styli35, other than by guide plate 31 as illustrated in FIGS. 1 and 2, isshown. A pluraiity of thin, rigid strips 7i) having oppositely facingilanged ends 71 are located transversely of aperture 25 in parallel,equally spaced apart relationship, ends 71 being a tight tit withinmating grooves 72 formed in two oppositely located sides of wall 26. Thetwo remaining sides of wall 26 are similarly grooved to receive aplurality of strips 73 in parallel, equally spaced apart relationship atright angles to strips 7), the spacing being the same as that for strips70, thereby forming a plurality of square apertures 74 in plan View.Each aperture 74 is adapted to permit a stylus 35 to pass therethroughin a sliding tit, strips 70 and 73 serving to locate all styli 35 in thehorizontal plane.

lt should be noted that upon a plurality of characters being required tobe printed in rapid succession the actuation of solenoid switches 58 bytheir respective activators 60 within transducer 52 is only momentary sothat the actuation of electromagnets 36 is also momentary, thus enablingcharacters to be printed by printing head Zit in very rapid succession.

It should also be noted that either head 2i) should be moved relative topaper 49 or paper 49 moved relative to head so that the charactersimprinted on paper 49 will be viewed in succession and not overprintedone on the other. An added improvement, therefore, may be anelectrically actuated device adapted to momentarily stop the relativemovement between head 2t) and paper 49 for the period during which acharacter is being printed.

It should also be noted that the principles explained herein may also beutilized in the manufacture of a completely electronic typewriter,thereby eliminating the large amount of mechanical movement which isstill evident in standard electrical typewriters, and furthermore, willresult in much quieter operation thereof.

The general design of the individual parts of the invention as explainedabove may be varied according to requirements in regards to manufactureand production thereof, while still remaining within the spirit andprinciple of the invention, without prejudicing the novelty thereof.

The embodiments ofthe invention in which an exclusive property orprivilege is claimed are defined as follows:

1. A printing head comprising a plurality of relatively rigid tubularmembers supported for axial movement within a housing, flexible tubularmeans for interiorly supplying ink to one end of each of said rigidtubular members from reservoir means at one end of said housing, eachremaining end of said rigid tubular members terminating in a stylushaving a restricted opening therethrough, a guide plate at an oppositeend of said housing to said exible tubular means, said styli extendingthrough said guide plate to terminate in a single plane,electro-mechanical elements for imparting said axial movement to saidrigid tubular members and thus to said styli, said guide plate servingto maintain said styli in close proximity to one another to ensure acompact printing head, said rigid tubular members spaced relativelyfurther apart than said styli due to the'presence of saidelectro-mechanical elements.

2. A printing head as defined in claim l wherein said electromechanicalelements comprise ferromagnetic discs concentric with said rigid tubularmembers and integrally attached thereto and electrical coils concentricwith said rigid tubular members, said coils supported by spacer meansmounted in said housing.

References Cited in the le of this patent UNITED STATES PATENTS 681,121Hudson Aug. 20, 1901 2,567,289 Libman Sept. 11, 1951 2,567,308Wockenfuss Sept. 11,V 1951 2,653,534 Wockenfuss Sept. 29, 1953 2,654,459Connolly Oct. 6, 1953 2,671,548 Anderson Mar. 9, 1954 2,997,152 DirksAug. 22, 1961

1. A PRINTING HEAD COMPRISINGA PLURALITY OF RELATIVELY RIGID TUBULARMEMBERS SUPPORTED FOR AXIAL MOVEMENT WITHIN A HOUSING, FLEXIBLE TUBULARMEANS FOR INTERIORLY SUPPLYNG INK TO ONE END OF EACH OF SAID RIGIDTUBULAR MEMBERS FROM RESERVOIR MEANS AT ONE END OF SAID HOUSING, EACHREMAINING END OF SAID RIGID TUBULAR MEMBERS TERMINATING IN A STYLUSHAVING A RESTRICTED OPENING THERETHROUGH, A GUIDE PLATE AT AN OPPOSITEEND OF SAID HOUSING TO SAID FLEXIBLE TUBULAR MEANS, SAID STYLI EXTENDINGTHROUGH SAID GUIDE PLATE TO TERMINATE IN A SINGLE PLANE,ELECTRO-MECHANI-